TALENs Modular Assembly for Precise Genome Editing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for targeted genome modification are robust and challenging to develop, particularly for specific and efficient nucleic acid editing tools that can modify genomes at predetermined locations.
Innovation Solution
The development of a platform for modular assembly of customized Transcription Activator-like (TAL) effector endonucleases (TALENs) that utilize a TAL effector DNA-binding domain and a modified FokI nuclease catalytic domain for sequence-specific binding and cleavage of target nucleic acid sequences, enabling precise genome editing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If robust methods for targeted genome modification are developed, then genome editing effectiveness is improved, but method complexity increases
Solution Approach 1:
The TALEN system divides the genome editing function into two separate components: a TAL effector domain for sequence-specific DNA binding and a FokI nuclease domain for cleavage. These components are fused to create modular TALEN proteins that can be independently designed and assembled, reducing overall method complexity while maintaining high editing effectiveness
Solution Approach 2:
The TAL effector domain provides universal sequence-specific binding capability through modular repeat units, each recognizing a specific DNA base. This universal binding mechanism can be applied to any target sequence by simply changing the repeat configuration, eliminating the need to develop entirely new methods for different targets and thereby reducing complexity
2Productivity
If sequence-specific binding and cleavage capabilities are enhanced, then mutation frequency is improved, but off-target effects increase
Solution Approach 1:
The system extracts and separates the binding function (TAL effector) from the cleavage function (FokI nuclease) into distinct modular domains. This separation allows the binding domain to be optimized for high specificity through modular repeat units, while the nuclease domain is activated only when properly positioned by specific binding, thereby reducing off-target effects while maintaining high on-target mutation frequency
Solution Approach 2:
The TAL effector domain acts as an intermediary that bridges the target DNA sequence and the FokI nuclease. It provides sequence-specific recognition through modular repeats and positions the nuclease precisely at the target site, ensuring that cleavage occurs only at the intended location and minimizing off-target effects while maximizing on-target mutation frequency
3Loss of time
If modular assembly platform is implemented, then assembly time is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The TALEN system segments the DNA binding domain into standardized modular repeat units, each 33-34 amino acids long and recognizing a specific DNA base. This segmentation allows rapid assembly of different TALEN variants by simply rearranging or replacing modules, dramatically reducing assembly time while the standardized interface maintains high manufacturing precision
Solution Approach 2:
The system uses parameter changes in the modular repeat units (specifically the repeat variable diresidues at positions 12-13) to encode different DNA base specificities. By changing these parameters within the modular framework, different target sequences can be targeted without redesigning the entire protein, reducing assembly time while the conserved modular structure ensures precise assembly
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This platform allows for rapid and effective targeted modification of nucleic acids and genomes, achieving high mutation frequencies and specificity in disrupting both protein-coding and non-coding genes, including microRNA genes and gene clusters, with minimal off-target effects.
Implementation Method 1
a TAL effector DNA-binding domain providing sequence-specific binding to a target nucleotide sequence
Implementation Method 2
a modified FokI nuclease catalytic domain
Data Source
AI summary
This application provides transcription activator-like effector nucleases (TALENs), polynucleotide sequences encoding the TALENs, expression cassettes for producing TALENs to target cleavage of nucleic acids, and methods of producing and using the TALENs.